The Chilkat.PrivateKey class an import RSA keys from the following formats: PEM, PKCS8, binary DER, PVK, and XML.

The Chilkat.PrivateKey can export to all of these formats as well.

Here's the procedure to get the Java Key Store private key into a Chilkat.SshKey object:
1) Follow the instructions in the StackOverflow article to export the private key from JKS to PEM.
2) Load a Chilkat.PrivateKey object with the PEM.
3) Export from Chilkat.PrivateKey to XML.
4) Load the XML into a Chilkat.SshKey object.